Improvement in pressure-gages



UNITED STATES PATENT CFFIGE.:

RIcnARnc. BLAKinoF CINCINNATI, onIo.

iMPROVI-:MENTIN PRssuRE-GAGES.

Spcciiication` forming part of Letters Patent No.`115,4270, dated May30, 1871.

`To all whom it may concern:

Be it known that I, RICHARD G. BLAKE, of

Cincinnati, Hamilton county,- State of Ohio, have invented certain newand useful Improvements in Pressure-Gages; and I do hereby de- 1 clarethe following to be `a sufficiently full,

y clear, and exact descriptionthereof to enable a one skilled in the artto which` my invention l appertains to make andnse it, reference being ahad t0 the accompanying drawing makingpart *of this specification.

`Nature and Objects of Invention. My invention relatesto the class ofgages which employs. au elastic metallic diaphragm to produce the motion`of the dial-nger; and

j y it consists, first, in a peculiar construction and combination ofthegaskets and follower for making the steam-joint between the diaphragm aand case, by which a perfect steam-jointis sey l cured and asolidmetallicbearing provided l for Vthe diaphragm to press against, therebypreventing variable indications at different f times under the samepressure; second, in a peculiar device for adjusting the leveragebetween thediaphragm and toothed segmental are, which operates `therevolving dial-fm ger.

Description of the Accompanying Drawing.

p, Figure 1 is a cross-section of a pressure'- gage embodying myinventlon. Fig. 2 1s a plan of the same.

I General Description. The case A of the gage is provided withthe`customary steam-supply portG, which terminates-inthe chamber D for thereception of the diaphragm E, which receives the steam-` pressure.Rubber gaskets F G are tted into the chamber aboveand below the outeriian ge of the diaphragm, anda metallic ringH, is

placed over the gasket G. lThe steam-joint is V made by the compressionof the gaskets by the follower I, whichis screw-threaded on the outyside to fit into the female screw provided in the chamber D; `As thefollower D necessa-` rily revolves in making the joint, the interveni ftion of the metallic ring H between the follower and upper gasket isnecessary to prevent thejfollower from chaiing the rubber.

When the follower is forced down in theact of making, the joints, thegaskets F G are forced together at the outer-edges in such a way as l tomeet and also fill up the threads of the screw in the chamber D,opposite the gaskets, in the manner shown, and thus prevent any escapeof steam past the edge of the gaskets or diaphragm in the event of itsaccidentally passing the faces of the gasket F. It has been found thatwhere rubber alone is used to press Iagainst the upper face of thediaphragm E the gage will record variable indications at dierent timesunder the same degreeof pressure, owing to the elastic and changeablenature-of the rubber. To guard against this contingency I construct thefollower I with a projecting annular collar, t, on the under side,which, when the gasket Gis sufficiently compressed to make a joint,rests solidly upon the diaphragm E, and gives a hard metallic surfacefor the diaphragm to press against. J is the customary segmental armwhich vibrates on the spindle-bearings a c', and serves to connect thediaphragm'with the revolving dialiinger-K, by means of pinion L, teeth jin the arc of the segment, pivoted bar M, connectin g-rod or pitman N,and bell-crank or elbowlever O, one leg of thelatter resting upon thediaphragm in themanner shown, and continually pressed against thediaphragm to preserve the contact by the spiral spring P. 'The bar M ispivoted'to the segment J at m, and connects with the rod N at the pointn, and the movement of the gage is adj usted by changing the distancebetween the'point n andthe center c', on which the segment oscillates.To effect this adjustment in a cheap manner, and

in a way that admits of, accurate and delicate degree of adjustment, Iprovide the lugs c c on the segment, and iit into the same thescrewthreaded adjusting-screws ol d', whose points' rest against thesides of the bar M in the man- J ner shown. It will be seen that thisdevice admits of delicate adjustment and retains the adjustmentpermanently, not being liable to slip or loosen.

It has been a common practice to t the bellcrank O snugly between thejaws of the bar R, and pivot the same on a stationary bolt or rivet,whichV passes through the jaws and bellcrank. This, if made` a tightfit, is liable to stick in such a way that the spring P cannot 2 lll5,420

return'it to the face of the diaphragm. If itted loose, it is shedding,and causes the gai-ge to record incorrect indications. To provide adevice not open to these objections, l insert a small spindle, e,tightly into the bell-crawl; 0, or form the same on solid, the spindlebeing centered on the ends. The jaws of the bar lit are fitted withjointed set-screws S, which engage in the centers of the spindle e. Afulcrnm is thus provided, which, while being free to oscillate ett alltimes, is not lisible to stick, and preserves the belLcrank in oneposition laterally.

Claims.

I clziini.- 1. In the described connection With the diaset my hand. l lRICHARD C. BLAKE.

Witnesses:

FRANK MILLWARD, J. L. WARTMANN.

